Referring to FIG. 1 of the drawings, there is shown a magnetic memory cell 10, known to the inventor. As will be seen, the cell 10 includes a magnetic storage element in the form of a magnetic tunnel junction (MTJ) 12. The cell 10 also includes a Y write/read line 14 for carrying a write/read current. The line 14 lies in the plane of the page. An X write line 16 extends into the plane of the page and carries a current for performing a write operation. A bottom electrode 18 is in contact with the storage element 12 as is shown in FIG. 1. The electrode 18 is coupled to an access transistor 22 by means of a conductive via 20. The access transistor 22 is made of drain terminal 23, source terminal 24, gate terminal 25 and conductor 26. The access transistor and other circuitry required to make memory devices are realized on semiconductor substrate 27 and are well known to one skilled in the art.
In the memory cell 10 the structures 14, 16, 18, 20, and 26 are realized by using metallic materials such as copper. In the quest to achieve high density memory devices, the physical dimensions of the cell 10 have to be reduced. Efforts to reduce the dimensions of the magnetic memory cell 10 in order to produce high density memory devices are being hampered by the phenomena of electro-migration in the metallic structures 14, 16, 18, 20 and 26 when the dimensions of these structures are reduced.